Is it a bad idea to use compact fluorescents with a motion sensor?

Factual Questions
1

The instructions that came with the motion sensor fixture (it’s an outside floodlight) don’t mention it, and power for the motion sensor is not in series with the bulb.

However, I wonder how much the life of the CFL would be affected by the cycling (figure 4-8 on/off cycles per day, maybe 300 days out of the year), and how much long term savings there would be (we’re talking 46 watts for the CFL floods vs. 180 watts for halogen floods). This is in Florida, so freezing temps generally aren’t an issue.

Thanks…

2

I don’t think cycling is a significant issue for quality (read: no cheap Chinese knockoffs) CFLs, but you might not like the results, since CFLs often take anywhere from 15 seconds to a minute to attain full brightness. They are getting better in that regard, but just be aware of it as a potential issue.

3

Hmm…thanks for your response, but it raises even more questions:

  1. What do you consider to not be “Chinese knockoffs” (since it seems like most things are made in China these days)? I’ve been using two different types, N:Vision, sold at Home Depot, and Sylvania, at BJ’s wholesale club. The N:vision soft white bulbs are very close to the color of incandescents, and I try to use them in all locations that aren’t dimmed. The Sylvanias have a much cooler color, but they’re also much cheaper (the floods and candelabra bulbs), so I use them outdoors.

  2. The standard N:vision (non-reflector) bulbs power on instantly (after the first turn on, which takes a couple of minutes) as long as they’re in a room-temperature environment. However, in the same environment, the N:vision floods have a longer warmup cycle, EVERY TIME they’re turned on. Why is this?

(and while we’re on the subject)

  1. What is it about dimmable CFLs that makes them so much more expensive?
4

  1. If it’s a major brand you recognize, I say go for it.

  2. Not sure, but probably some combination of differences in phosphor chemistry and ballast electronics. Note that outdoors, in colder temps, bulbs generally tend to take longer to attain full brightness; a characteristic which worsens with decreasing temperature.

  3. They’re dimmable. Really. I don’t believe they cost any more to manufacture, but simply the added benefit of being dimmable means they can sell them for a higher price.